实用太阳能热水器贮水箱水位水温测量变送器

摘要

A kind of transmitter which can be used to measure watertemperature and water level is designed. Capacitive water level sensor completes the transformation from water level to capacitance. Current-type temperature sensor realizes the transformation from water temperature to current. Combining the output of capacitance-pulse width and current-pulse width transformation circuit with width-pulse proportional to water level and water temperature,both pulses synthesize a one-way measuring signal and two-ways transmission.The main points of transmitter design are listed, and the technological steps of improving credibility are provided.Experiments have proved that this kind of transmitter has high antinterference,high stability and reliability. The precision meets user's requirements.%设计了一种水位、水温测量变送器。电容式水位传感器完成水位—电容的转换，电流式温度传感器实现水温—电流的转换，电容—脉宽、电流—脉宽变换电路输出与水位、水温成比例的调宽脉冲。这两种脉冲综合成一路测量信号，两线制传输。给出了变送器的设计要点，提出了提高可靠性的工艺措施。实验证明，该变送器抗干扰能力强，稳定可靠，精度满足用户的需要。